Pixel tube for field-emission display device

Abstract

A pixel tube for a field-emission illumination/display device includes a sealed container, an anode electrode, a cathode electrode and a shielding electrode. The sealed container has a light permeable portion. The anode electrode is disposed in the sealed container and adjacent to the light permeable portion. The cathode electrode is arranged in the sealed container facing the anode electrode and includes a cathode supporter and a carbon nanotube yarn, the carbon nanotube yarn attached to the cathode supporter and extending toward the anode electrode for emitting electrons therefrom. The shielding electrode is disposed on a surface of the sealed container and surrounds/encircles the carbon nanotube yarn.

1. A pixel tube for a field-emission display device, comprising:
 a sealed container having a light permeable portion; 
 an anode electrode positioned in the sealed container at a position adjacent to the light permeable portion; 
 a cathode electrode arranged in the sealed container and facing the anode electrode, and comprising a cathode supporter and one carbon nanotube yarn attached to the cathode supporter and extending toward the anode electrode, the carbon nanotube yarn being supported by the cathode supporter, the carbon nanotube yarn being configured for emitting electrons therefrom; and 
 a shielding electrode positioned on a surface of the sealed container, the shielding electrode surrounding the carbon nanotube yarn, wherein the surface of the sealed container surrounds the carbon nanotube yarn. 
 
     
     
       2. The pixel tube as claimed in  claim 1 , wherein the shielding electrode is annular. 
     
     
       3. The pixel tube as claimed in  claim 1 , wherein the shielding electrode is a conductive film. 
     
     
       4. The pixel tube as claimed in  claim 3 , wherein the conductive film is comprised of a material selected from the group consisting of gold, silver, copper, and aluminium. 
     
     
       5. The pixel tube as claimed in  claim 2 , wherein the shielding electrode and the sealed container are coaxial. 
     
     
       6. The pixel tube as claimed in  claim 3 , wherein the shielding electrode is directly positioned on an inner surface or an outside surface of the sealed container. 
     
     
       7. The pixel tube as claimed in  claim 1 , wherein a conductive adhesive connects the carbon nanotube yarn and the cathode supporter. 
     
     
       8. The pixel tube as claimed in  claim 1 , wherein an end of the carbon nanotube yarn is welded to the cathode supporter. 
     
     
       9. The pixel tube as claimed in  claim 1 , wherein the anode electrode is an aluminum film. 
     
     
       10. The pixel tube as claimed in  claim 1 , wherein the carbon nanotube yarn has a length in a range from about 0.1 millimeters to about 10 millimeters. 
     
     
       11. The pixel tube as claimed in  claim 1 , wherein the carbon nanotube yarn has a diameter in a range from about 1 micrometer to about 1 millimeter. 
     
     
       12. The pixel tube as claimed in  claim 1 , further comprising a phosphor layer arranged on the light permeable portion in the sealed container. 
     
     
       13. The pixel tube as claimed in  claim 1 , wherein the shielding electrode is outside of the sealed container. 
     
     
       14. A pixel tube for a field-emission display device, comprising:
 a sealed container having two opposite ends, the sealed container further comprising a light permeable portion arranged at one end; 
 an anode electrode and a cathode electrode arranged on the two ends, respectively, the anode electrode being adjacent to the light permeable portion, the cathode electrode comprising a cathode supporter and at least one emitter positioned on the cathode supporter and extending towards the anode electrode; and 
 a shielding electrode surrounding the at least one emitter and contacting a surface of the sealed container, wherein the surface of the sealed container surrounds the at least one emitter. 
 
     
     
       15. The pixel tube as claimed in  claim 14 , wherein the shielding electrode is attached to an inner circumferential surface of the sealed container. 
     
     
       16. The pixel tube as claimed in  claim 14 , wherein the shielding electrode is spaced from the carbon nanotube yarn, and the surface of the sealed container is located between the shielding electrode and the carbon nanotube yarn. 
     
     
       17. The pixel tube as claimed in  claim 14 , wherein the cathode supporter has two ends opposing each other, one end of the cathode supporter is inside the sealed container and in contact with the at least one emitter, an intermediate portion of the cathode supporter is substantially hermetically sealed in an end wall of the sealed container, and the other end of the cathode supporter extends to outside of the sealed container. 
     
     
       18. A pixel tube for a field-emission display device, comprising:
 a sealed container having a light permeable portion; 
 an anode electrode positioned in the sealed container at a position adjacent to the light permeable portion; 
 a cathode electrode arranged in the sealed container and facing the anode electrode, and comprising a cathode supporter and a carbon nanotube yarn, wherein the carbon nanotube yarn is attached to the cathode supporter and extends toward the anode electrode, the carbon nanotube yarn being configured for emitting electrons therefrom; and 
 a shielding electrode positioned on a surface of the sealed container, the shielding electrode surrounding the carbon nanotube yarn, wherein the shielding electrode is annular, and the shielding electrode and the sealed container are coaxial, the surface of the sealed container surrounds the carbon nanotube yarn, and the shielding electrode is outside the sealed container. 
 
     
     
       19. The pixel tube as claimed in  claim 1 , wherein the cathode supporter has two ends opposing to each other, one end of the cathode supporter is inside the sealed container extending towards the anode electrode, an intermediate portion of the cathode supporter is hermetically sealed in an end wall of the sealed container, and the other end of the cathode supporter extends outside of the sealed container. 
     
     
       20. The pixel tube as claimed in  claim 1 , wherein only one end of the carbon nanotube yarn is attached to the cathode supporter, and the carbon nanotube yarn extends substantially toward the anode electrode along a direction from an end of the cathode supporter to the anode electrode.